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ACID DEPOSITION AND FOREST ECOSYSTEMS. Chapter 3.11. Acid Deposition. Technology is great but it also contributes to acid deposition.
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ACID DEPOSITION AND FOREST ECOSYSTEMS Chapter 3.11
Acid Deposition • Technology is great but it also contributes to acid deposition. • Coal-burning plants, cars, and trucks, metal smelters, and oil refineries provide energy, transport, and materials for the industrial world, but at the same time produce oxides of sulfur and nitrogen, among the most dangerous of air pollutants.
The Problem of Combustion • Sulfur dioxide (SO2) and Nitrogen oxides (NOx) are released into the atmosphere by burning fossil fuels. • Sulfur and Nitrogen enter the atmosphere they may combine with water droplets to form acids. • The acids return to the surface of the Earth in the form of snow or rain, called ACID PRECIPITATION.
ACID PRECIPITATION KILLS: • Fish • Soil Bacteria • Aquatic Plants • Terrestrial Plants • The sulfur and nitrogen oxides released from tailpipes and smokestacks do not always enter the water cycle in the atmosphere.
Sulfur and nitrogen compounds may remain airborne and settle out in the dry state – DRY DEPOSITION • Dry Deposition enter the water cycle and form acid as it combines with moisture • CAN BE FOUND: • Dew on lawns • Surface of lakes • Water inside your respiratory tract
THE EFFECTS OF ACID PRECIPITATION • Direct effects on Humans: • Medical effects • Accelerated respiratory problems • Examples: Asthma, bronchitis • Cause eyes to water • Irritate skin • Dissolving marble statues • Corroding metal • Dulling car finishes • Damage to buildings
Effects on Ecosystems • Damage to leaves • Damaged to tissues of trees become more susceptible to fungal or bacterial infections.
EFFECTS OF ACID RAIN Important to Nitrogen Cycle Acid falls to Soil Acid Falls to Soil Promotes growth of Moss Kills Bacteria Releases Aluminum in the soil Reduces Nutrients in Trees Damage tree Roots
pH – Potential Hydrogen • A measure of the acidity or alkalinity (basic) in the solution • Measured using pH meter • pH is a scale from 0 – 14 where: • 0 – 6.9 = Acidic • 7.0 = neutral • 7.1-14 = Basic 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 • A pH of 3 is 10 times more acidic than pH of 4 More Basic More Acidic
pH of Normal rain water • pH of 5.6 • pH of Acid Rain • Range from 4.5 to 5.6; average 5.0
pH corresponds to the concentration of Hydrogen Ie. Low pH = high H
HOMEWORK • Read page 116 -118 • Fill in handout • Answer Questions #1-4 page 118